Gear-drawing instrument.



C. H. SAPPEH.

GEAR DRAWING INSTRUMENT.

APPLICATION man FEL-1.1916.

l 219 '783. Patented Mar.20,1917. 2 SHEETS-SHEET l.

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GEAR DRAWING INSTRUMENT. APPLICATION FILED FEB. l1. 191s.

'1,21 9,782. Patented Mar. 20, 1917.

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CHARLES I-I. SAPPER, OF NORFGLK, VIRGINIA.

GEAR-DRAWING INSTRUMENT.

Specification of Letters-Patent.

Patented Mar. ao, reir.

Application led February 4, 1916. Serial No. 76,118.

To all whom t may concern:

Be it known that I, CHARLES H. Sarrieri, a citizenl of the United States, and a resident of Norfolk, in the county of Norfolk and State of Virginia, have: invented a new and Improved Gear Drawing Instrument, of which the following is a full, clear, and ex act description.

My invention has for its object to provide an instrument for drawing gears which may be adjusted for drawing gears with any desired number of teeth and of any pitch diameter. The instrument may be operated to trace the shape f the teeth over a master rino and b7 means Jrovided move a )en over paper to draw the gear teeth thereon, the said means being adjustableV to draw the gear of the desired diameter and the teeth of the desired depth.

Still other objects of the invention will appear in the following' specification, in which the preferred form of my invention is described.

ln the drawings similar reference characters denote similar parts in all the views, in which Figure 1 is a plan View of my invention;

Fig. 2 is a side elevation of Fig. l;

Fig. 3 is a transverse sectional elevation of Fig. l;

Fig. 4.- is a side elevation showing the instrument with another type of base, partsl of the base being broken away to illustrate features of the construction;

Fig. 5 is anV enlarged view showing the marking mcans, the beam on which the marking means is mounted being illustrated in section Fig. 6 is a sectional View of the link which l connects the two levers, the means for securing the link to the lever articulated to the beam being illustrated;

Fig. 7 is a fragmentary sectional view of the link which is articulated to the beam;

Fig. 8 is a fragmentary sectional view illustrating the means for articulating the lever to the beam Fig. 9 is a sectional view of the frame on which the levers are mounted; and

Fig. 10 is a view illustrating a tooth which has been' drawn with the instrument, the relative positions of the teeth of the master ring and the teeth of the gear drawn therefrom being indicated.

By referring to the drawings, it will be seen that a base 10 is provided having vertical guideways 11 in which thumb tacks l2 are disposed, it being possible to press these thumb tacks 12 down into a drawing board to hold the base 10 relatively thereto. |The base 10'has inner threads 13 with which mesh threads on a supporting ring 1-1 having an annular recess 15 in which a master guide member 16 is detachably disposed, this master-guide member 16 being held in position relatively to the supporting ring 14 by a pin 17, and being provided with guide means 18 which may be in the form of gear teeth, as shown iir Fig. 1 of the drawings. The master guide member 1G may be removed from the supporting ring 14, so that another master guide member may be substituted therefor.

The supporting ring 14C has an inner circular groove 19 in which travel rollers 20 which are rotatably mounted on a supporting frame 21, it being possible for the supporting frame 21 to rotate relatively to the supporting ring 14 and the master guide member 16. On the supporting frame 21 there is disposed a frame 22, this frame 22 being held in position on the supporting frame 21 by screws 23, in a manner readily understood. Secured to the frame 22 and extending therefrom, there are guides 211 in which is disposed a beam 25, it being possible for this beam 25, which extends across the instrument, to move longitudinally. Fulcrumed to the frame 22 at 26 there is a slotted lever 27, the lever 27 being articulated to the beam 25 at 2S. This slotted lever 27 is provided for moving the beam longitudinally, and, in order to permit of the free movement of the beam, the slotted lever 27 where it is articulated at 28 to the beam, has a slot 29 in which a pin 28a`is disposed'. Another lever 30 is fulcrumed to the frame 22 at 31, and to this lever 30 there is secured a tracer 32 which is adapted to travel in the guide means 1S, which may be made to represent teeth of a spur, worm or other gear. A link 33 is articulated to the lever at 34, the terminal 35 of the link 33 being disposedl under the slotted lever 27 and being preferably separated therefrom by a washer 36. A screw 37 is disposed upwardly through an orifice 38 in the end 35 of the link 33, the head 39 of the screw 37 abutting against the end of the link 33, around the orifice 38. This screw 37 also extends up through the washer, through the slot in the lever 27 and through an orifice Vio 41.0 in a slot-engaging member Li1, a wing nut 12 meshing with the thread on the screw 37 and pressing against the slot-engaging member 1:1 i'or holding a tin t3 on the slot-engaging member L11 down in the slot in the lever 27.

It will be understood that by turning the nut 12 the end 35 of thelink 33 may be moved to or ilfrom the beam 25 as desired, the iin 13 on the slot-engaging member 11 sliding in the slot in the lever 27 until the end 35 ot the link 33 has reached the position desired with reterence to the slotted lever 27, when the wing nut 4t2 may be turned home to press the slot-engaging member t1 against the lever 27 and the head 39 ot the screw 37 against the under side ot the end ot the link 33. Further movement ot the end 35 of the link longitudinally ot' the slotted lever 27 is prevented, while the construction permits oi a rocking movement of the end 35 of the link 33 relatively to the said slotted lever.

1t will be seen. that with the movement ot the tracer 3Q in the guide means 13, the beam 25 will be operated by means ot' the lever 30, the link 33 and the slotted lever 27. r1`he marking means is mounted o-n the beam 25, and is adapted to move longitudinally of the beam 25 and be held in adjusted position. The marking, means has a pencarrier te with a recess in which the beam Q5 is disposed, the pen-carrier being provided with a wedge member 16 for holding the pen-carrier ist in adjusted position rela tively to the beam, this wedge 46 being secured in position by means of a screw 17 which is disposed in an orifice 18 in the pen-carrier 4A and which meshes in a threaded orifice f19 in the wedge member 16. The pen-carrier te has a circular opening 50 in which a tube 51 is disposed, this tube 51 having a shoulde.' which engage. the under side o'l" the pen carrier 11i, the tube 51 being held upwardly with its shoulder against the under side ot the peirearrier by means ot a nut 53 which meshes with a thread 54: on the tube 51. A spring 55 serves to hold the nut 53 yieldingly upwardly with the tube 51 at its shoulder 52 engaging the under side of the pen-carrier. Extending from the pen-carrier la there are locking means 56 which engage locking means 57 on the tube 51 when the tube 51 is pressed upwardly by means ott the nut 53 and a spring 55; but when the nut 53 is screwed upwardly relatively to the tube 51, it is possible to free the locking means 5G, and the locking means 57, so that the tube 51 may be rotated relatively to the pencarrier 44:, it being possible to lock the tube 51 relatively to the pen-carrier 44g in its new position by the means wnich have been described. Hinged to the bottom ot the tube 51 at 53 there is a pen arm 59, which car ries a pen 60, the pen arm 59 having an opening 61 in which the lower end o a rod 62 is disposed, this rod 69. being connected with the pen arm 59 by means of a pin and slot G3. The upper end of this rod (S2 is threaded, and a nut 611 meshes with the thread on the rod G2, by means of which and a spring 65 which engages a washer 66 at the top ot the tube 51, the rod 62 is held yieldingly upward, it being possible however, by turning the nut 64e, to permit the rod 32 and the pen arm to descend until the pen G0 rests on the paper over which the base 10 is disposed. But when the instrument is to be adjusted, the nut 6e may be turned, thereby raising the rod G2 until the pen (3() is raised trom the paper.

There is a scale G7 on the beam 25, and by referring to this scale, it is possible to adjust the pen-carrier la relatively thereto, to draw gears of any desired size, the depth ot the teeth of the gears being regulated by means ot the adjustment of the end 35 of the link 33 relatively to the slotted lever 27, there being a scale 27" on this slotted lever 27, so that the desired position ot the end oi the link 33 may be readily determined.

A master guide member 16 having any desired number oi' teeth, may be mounted on the supporting ring 14, and may be held in position relatively thereto by the pin 17, and wit.'L this master guide member' gears may be drawn having the same number oi' teeth, and ot any desired pitch diameter by the adjustment ot the pen-carrier L14: relatively to the beam 25, it being possible to regulate the depth of the teeth which are to be drawn, by the means which have been described.

1n Fig. 10 of the drawings, there is illusw trated a tooth oi a gear which is drawn by the instrument which is the subject matter ot this application, the tooth being ot less diameter than the master guide member irom which it is drawn.

The hase 10 which is shown in 2 and 3 of the d "awings may be used to draw gears which are of the same or of less diameter than the master guide member, but when it is desired to draw gears having a greater diameter than the master guide member, l prefer to make use ot a base 10, in lieu ot the base 10. This base 10et has an outer thread which meshes with the inner thread 68 on the supporting ring 14. This base 10n is illustrated in Fig. et of the drawings, and when it used, the pen-carrierl #i is disposed on the beam beyond the supporting ring 111.

The instrument has a centering pen 69 which may be raised, as illustrated in TEig. 3 of the drawings, when a very small gear is to be drawn. The beam 25 is provided not only with the scale 67, but also with a second scale 67 one ot these scales being made use of when the pen arm 59 eXtends outwardly, as illustrated in Fig. 3 ot' the drawings, and the other. scale aeing used when the pen arm 59 extends inwardly as illustrated in F ig. 4. 'Vihen a bevel o-r miter gear is to be drawn, a gear may be laid out on a separate piece et paper having the proper number of teeth and the two tace circles. This piece of paper may then be located under the tracing, and the radial teeth lines drawn from tace circle to tace circle, the draftsman being guided as to spacings by the layout upon the paper which has been drawn with the instrument. lfllhen a circle is to be drawn, this may be done by disposing the tracer 32 in an annular groove 70.

When the gear is to be dotted, the pen arm 59 is held in raised position by the means which have been described, and as the tracer 32 travels inthe guide means, the nut 64 is tapped so as to press the rod G2 down periodically, which permits the pen arm 59 and the pen G0 to tall to paper making dotted lines.

Having thus described my invention, what l claim as new and desire to secure by Letters Patent, is:

l. In a gear drawing instrument, a master member having guide means, a beam disposed across the master member, a marking member carried by the beam, a tracer for moving in the guide means or' the master member, and means operable by the tracer for actuating the beam.

2. in a gear drawing instrument, a master 'member having guide means, a beam, a

marking member adjustably mounted on the beam, means to secure the marking member in adjusted position on the beam, a tracer for moving in the guide means or' the master member, and means operable by he tracer for actuating the beam.

ln a gear drawing instrument, a master member having guide means, a beam, a marking member carried by the beam, a tracer for moving in the guide means of the master member, a lever for operating the beam, and means adjustable relatively to the lever and normally secured thereto 'for actuating the lever, the said means being operable by the tracer.

il. In a gear drawing instrument, a master member having g'uide means, a beam, a marking member carried by the beam, a tracer for moving in the guide means of the master member, a lever for operating the beam, and meansV adjustable relatively to the lever and normally secured thereto for actuating the lever, the said means ing operable by the tracer.

5. .ln a gear drawing instrument, a master member having guide means, a frame for moving relatively thereto, a beam, a marker carried by the beam, a tracer for traveling in the guide means, a lever pivoted to the frame for operating the beam, a lever pivoted to the frame and to which the tracer is secured, and a link connecting the two levers.

G. in a gear drawing instrument, a master member having guide means, a trame tor moving relatively thereto, a beam, a marker carried by the beam, a tracer for traveling in the guide means, a lever pivoted to the frame tor operating the beam, a second lever pivoted to the `frame and to which the tracer is secured, and a linlr secured to one ot' the levers and adjustably secured to the other lever.

i". in a gear drawing instrument, a circular master member havmo' einde means.`

'C3 b a trame for rot-ating relatively thereto and provided `with guides, tracer for traveling in the guide means in the master member, a beam disposed for moving' in the guides, and means tor operating the beam aud adapted to be actuated by the tracer.

S. 1n a gear drawing instrlnnent, a master member having guide means, a frame for rotating relatively thereto and provided with guides, a tracer tor traveling in the guide means ,in the master member, a beam disposed for moving in the guides, a lever fulcrumed to the traine and articulated to the beam for operating the latter, a lever secured to the trame to which the tracer is secured, and a link connecting the two levers.

9. n a gear drawing instrument, a support, a master ring having guide means, detachably secured to the support, a trame movable relatively to the support and provided with guides, a beam disposed in the guides -for moving relati'velv thereto, mark ing means mounted on the beam, a lever fulcrumed to the frame and articulated to the beam for moving the latter, a tracer -tor traveling in the guide means of the master ring, and means connecting the tracer with the lever for operating the latter.

l0. In a gear drawing instrument, a support, a master ring having guide means, detachably secured to the support, a trame movable relatively to the support and provided with guides, a beam disposed in the guides for moving relatively thereto, marking mea-ns mounted on the beam, a lever fulcrumed to the tramo and articulated to the beam for moving` the latter, a tracer for traveling in the guide means ot the master ring, a second lever ulcrumed to the lever on which the tracer is mounted, and a link connecting the two levers.

l1. In a gear drawing instrument, a support, a master ring having guide means detachably secured to the support, a tracer for traveling in the guide means in 'the master ring, a frame disposed over the master ring and rotatable relatively to the support, a

beam disposed transversely ot the master ring', guides on the trame in which the beam is adapted to move, and adjustable means mounted on the trame and operable by the tracer for actuating' the beam.

12. ln a gear drawing' instrument, a support, a master ring' havin); guide means detachably secured to the support, a tracer adapted to travel in the ,guide means, a frame disposed over the master ring and rotatable relatively to the support, a beam disposed transversely ot' the master ring', ,guides on the trame in which the beam is adapted to move, a slotted lever tulerumed u'to the frame and articulated to the beam, a

second lever tulerumed to the trame, to which the tracer is articulated, a link articulated to the second lever', and means adjustably secured to the first lever at its slot to which the link is articulated.

13. In a ,qear drawing' instrument, an operating' beam, a pen-carrier mounted on the beam and provided with a tube, a pen arm hinged to the tube, a red secured to the pen and having' a threaded portion, and a nut meshing' with the thread and abutting' against the tube tor moving the pen arm relatively to the tube.

14. In a gear drawing instrument, an operating' beam, a pen-carrier mounted on the beam and provided with a tube, a pen arm hinged to the tube, a rod secured to the pen and having a threaded portion, a nut meshing' with the thread and abutting' against the tube tor moving),- the pen arm relatively to the tube, and resilient means tor holding the nut yielding'ly relatively to the tube.

l5. ln a gear drawing' instrument, a pencarrier having' an opening' and locking' means, a tube disposed in the opening' and having' a thread and a shoulder against which the pen-carrier normally rests, companion locking; means on the tube which en- Q'an'o the locking' means on the pen-earrier when the pen-carrier pressed against the shoulder, and a nut meshing' with the thread on the tube for pressingr the peu-carrier against the shoulder.

16. In a Ie'ear drawing instrument, a pencarrier having an opening' and loeliinp; means, a tube disposed in the opening and having' a thread and a shoulder against which the pen-carrier normally rests, companion locking' means on the tube which en ,(agge the locking' means on the pen-carrier when the pen-carrier pressed against the shoulder, a nut meshing' with the thread on the tube lor pressing' the pen-carrier against the shoulder, a pen arm hinged to the tube, a threaded rod secured to the pen arm and disposed in the tube, and a nut meshing with the thread on the rod for holding the pen arm relatively to the tube.

17. ln a gear drawing' instrument, a supporting' ringr having' a thread, a detachable base having' a thread meshing,- with the thread on the supporting' ring', a master rin?,` having' ,duide means mounted on the support, a trame rotatable relatively to the support and provided with guides, a. beam disposed in the guides :t'or moving' relatively thereto, marking' means mounted on the beam, a lever tulcrumed to the frame and articulated to the beam for moving" the latter, a tracer 'for traveling' in the ,guide means in the master ring, and means conA nesting' 'the tracer with the lever for operating the latter.

i8. ln a gear drawing' instrument, a master member hai/ine; guide means, a marking member, a 'tracer Jor moving; in the Q;nide means on the master member, and means rotatably mounted relatively to 'the master member and operable by the tracer tor actuating the marking member.

19. ln a ,qear drawing' instrument, a support having' a circular groove, a master ring,y having' ,guide means and mounted on the support, a trame rotatable relatively to the support, rollers mounted on the trame for traveling` in the circular groove, guides on the trame, a beam disposed in the guides for moving' relatively thereto, marking means mounted on the beam, a lever fulerumed to the frame and articulated to the beam for movinp; the latter, a tracer for traveling in the ,guide means in the master ring, and means connecting; the tracer with the lever Vfor operatingthe latter.

20. ln a Q,'ear drawing' device, a master member having;` guide means, a trame, means for directing' the movement or" the frame relatively to the master member, a marker, a tracer tor traveling' in the a'uide means, and means mounted on the :trame and movable relatively thereto by which the tracer adapted to operate the marker.

2l. ln a gear drawing' instrument, a master member having Iguide means, a rotatably mounted frame movable relatively to the master member, a tracer for traveling' in the lguide means, and means mounted on the frame and movable relatively thereto by which the tracer is adapted to operate the marker.

ln testimony whereof I have signed my name to this specification in the presence et two subscribing; witnesses.

CHARLES ll. SAPPER.

Witnesses WV. E. Knnrwoon, D. E. Knisrnn.

Copies of this patent may be obtained for five cents each. 'by addressing' the "Commissioner of Patents, Washington, D. C. 

